Nailing attachment for pneumatic hammers



June 1949. P. VAN SITTERT ETAL 2,472,353

NAILING ATTACHMENT FOR PNEUMATIC HAMMERS Filed Sept. 7, 1945 INVENTORJS- PAUL VAN SITTERT WILLIAM E. BART j ATTOzNYS Patented June 7, 1949 UNITED STATES PATENT OFFICE NAILING ATTACHMENT FOR PNEUMATIC HAMMERS Application September 7, 1945, Serial No. 615,042

4 Claims. (Cl. 146.1)

This invention relates to improvements in percussive tools, more particularly those for driving nail sets and comprising guides or guards to assist the operator in holding the tool upon the head of a nail to be driven.

One of the objects of the invention is the provision of a tool of this character of simple construction and correspondingly low cost.

-Another object of. the invention is the provision in a tool of this character of guard means which may be mounted directly upon the nail set in such manner as to be readily assembled upon or removed from the set.

Other objects and features of novelty will appear as we proceed with the description of those embodiments of the invention which, for the purposes of the present application, we have illustrated in the accompanying drawing, in which Fig. 1 is a fragmental elevational view of a percussive tool equipped with a nail set according to the present invention.

Fig. 2 is a longitudinal sectional view taken substantially on the line 2--2 of Fig. 1 and showing the condition of the tool at the stage at which a nail has been driven down flush with the work.

Fig. 3 is a cross-sectional view on a larger scale, taken substantially on the line 3-3 of Fig. 2.

Fig. 4 is a view similar to that of Fig. 1, showing a modified form of the invention.

Fig. 5 is a longitudinal sectional view on the line 5-5 ofFfg. 4, but with the end of the guard flush with the end of the nail set as it would be at the completion of a nail driving operation, and

Fig. 6 is a detail sectional view taken substantially on the line 5-6 of Fig. 4.

In the drawing we have illustrated at lo a fragment of the casing of a percussive tool having a cylinder II in which a reeiprocatory hammer I2 is movable by compressed air or other power means. In axial alignment with the cylinder H there is a bore I3 of somewhat smaller diameter flared at its outer end, in which is slidably mounted the inner portion l4 of a nail set disposed to receive blows from the hammer l2. The

casing of the tool also comprises a cup-shaped extension l5 which is threaded onto the reduced end portion it of the larger part of the casing. The inner end of the cup I5 is split by a slot I! which extends through a thickened part 18 of the rim of the cup. This thickened part is drilled tangentially and threaded to receive a screw ill by means of which the split parts of the cup may be drawn together for tightly locking the cup to the principal part III of the casing.

Within the cup there is disposed a rubber block 2 20 with a central opening in which is received the outer constant'diameter part 2| of the nail set, th base of the cup also having a bore 22 therethrough aligned with the opening in block 20 and with the bores l3 and II of the tool. A collar 23 on the nail set engages the inner end of th rubber block 20.

Around the constant diameter portion 2| or with a shallow groove 28 surrounding the guard 24, andin this groove there is a split spring ring 29 which retains the balls. v

As will be apparent, these parts permit a certain limited relative movement longitudinally between the set andthe guard. A coil spring 30 surrounding the set 2| bears at one end against the cup l5 and at the other end against the guard 24, the latter being preferably counterbored to receive the spring, th upwardly projecting rim 34 of the guard constituting a stop to limit the movement of the cupand guard toward each other. In Fig. 2 we have shown a nail N driven into the workpieces 32 and 33, and have shown the condition of the tool at-the time when the final blows are delivered.

When it is desired to remove the guard 24 the operator, with the=aid of a pointed instrument, springs the ring 29 out of its groove 28 and moves it lengthwise of the guard far enough to completely clear the groove, when the balls 26 may be permitted to fall out of the holes 21, thus freeing the guard 24 from the set. In assembling the guard upon the setthe guard is first slid into place and held substantially in the position of Fig. 2 against th action of the spring 30, the guard being turned to align the holes 21 with the groove 25. Then theballs are inserted into the holes 21 and caused to extend into the grooves. The split ring 29 is then moved along until it rests within the groove 28, thereby locking the balls in operative position.

In the modification illustrated in Figs. 4, 5 and 6, the cup 35 corresponds to the cup l5 0! the above described form of the invention, and nail set 4| corresponds to set 2|. The internal parts of the tool not illustrated in Figs. 4, 5 and 6 may be identical with those of Figs. 1, 2 and 3.

A guard 44 is mounted upon the set 4| for relative sliding movement, being urged outwardly upon the set by a coil spring 50 which surrounds the set between the cup 35 and the guard. Guard 44 is shaped approximately like a sleeve, out is open on one side for a portion of its length as indicated at 5|. and in line with this opening the bore of the sleeve is enlarged somewhat as shown at 52 in Fig. 5. At the outer end of the enlargement 52 there is a groove 53. An annular groove 54 in the set 4| receives a spring ring 55 having a pair of outwardly projecting ends 56. This ring, as it travels up and down bears against the bore enlargement 52, andwhen it strikes the upper end of this enlargement it stops further movement of the guard outwardly upon the set.

In case it becomes desirable to remove the guard 44 in servicing the tool the operator pushes the guard inwardly against the action of the spring 50 until the groove 53 comes opposite the ring 55. He then spreads the ends 56 of the rin to cause the ring to leave the groove 54 and enter the groove 53, after which the guard may be pulled off the set 4|. The reverse procedure is followed in assembling the guard upon the set.

In the foregoing description we have neces-- sarily gone somewhat into detail in order to explain fully the particular embodiments of the invention herein illustrated, but we desire it to be understood that such detailed disclosures are not to be construed as amounting to limitations, except as they may be included in the appended claims.

Having thus described our invention, we claim:

1. In a percussive tool of the character described, a casing, a reciprocatory hammer therein, a nail set extending into said casing in line with said hammer to receive blows therefrom, said set having a cylindrical portion of uniform diameter projecting beyond the casing, a guard on the projecting uniform diameter portion of said set, said guard having a uniform bore slidably fitting said projecting portion, spring means for biasing said guard outwardly on said set, said set having a longitudinal groove, said guard having a radial opening adapted to register with said groove, and a detent held in said opening and movable in said groove for limiting outward movement of the guard.

2. In a percussive tool of the character described, a casing, a reciprocatory hammer therein, a nail set extending into said casing in line with said hammer to receive blows therefrom, said set having a cylindrical portion of uniform diameter projecting beyond the casing, a guard on the projecting uniform diameter portion of said set, said guard having a uniform bore slidably fitting said projecting portion, a coil spring surrounding said set between said casing and said guard for biasing the guard outwardly on the set, said set having a longitudinal groove, said guard having a circular opening adapted to register with said groove, a detent in said opening and movable in said groove for limiting the outward movement of the guard, and means for holding said detent in operative position including a spring ring carried by said guard over said detent. which ring when withdrawn permits removal of said detent to enable the guard to be withdrawn from the set.

3. In a percussive tool of the character described, a casing, a reciprocatory hammer therein, a. nail set extending into said casing in line with said-hammer to receive blows therefrom. said set having a cylindrical portion of uniform diameter projecting beyond the casing, a guard on the projecting uniform diameter portion of said set, said guard having a uniform bore slidably fitting said projecting portion, a coil spring surrounding said set between said casing and said guard for biasing the guard outwardly on the set. and cooperating means on said set and guard for limiting the outward movement of the guard, said cooperating means comprising a spring ring which when withdrawn permits said cooperating means to be disassembled to enable the guard to be withdrawn from the set.

4. In a percussive tool of the character described, a casing, a reciprocatory hammer therein, a nail set extending into said casing in line with said hammer to receive blows therefrom, said set having a cylindrical portion of uniform diameter projecting beyond the casing, a guard on the projecting uniform diameter portion of said set, said guard having a uniform bore slidably fitting said projecting portion, spring means for biasing said guard outwardly on said set, said set having a longitudinal groove, said guard having a circular opening adapted to register with said groove, and a ball held in said circular opening and movable in said groove for limiting the outward movement of the guard.

PAUL VAN SIT'I'ER'I. WILLIAM E. BARTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 13,724 Lindberg May 12, 1914 1,213,970 Sturtevant Jan. 30, 1917 1,449,136 Yates Mar. 20, 1923 1,776,646 Wilson Sept. 23, 1930 1,808,452 Cousins June 2, 1931 2,272,760 Allen Feb. 10, 1942 FOREIGN PATENTS Number Country Date 362,518 France June 27, 1906 

